Foremost Corporation manufactures boxes. The estimated number of boxes sold for the first three months of the current year are: Month January February March Sales 3,000 4,200 3,900 Finished goods inventory at the end of December was 900 units Ending finished goods inventory is equal to 20 percent of the next month's sales. General Corporation expects to sell the boxes for $5 each. April sales is projected at 4,500 boxes. How many boxes should be produced in February? a. 4,140 boxes b. 3,900 boxes c. 4,260 boxes d. 4,200 boxes